Question

Consider an electric dipole in a uniform electric field. In which orientation does the dipole-field system have the greatest potential energy? when the dipole moment and the electric field are parallel when the dipole moment and the electric field are antiparallel when the dipole moment makes the 60∘ angle with the electric field when the dipole moment and the electric field are perpendicular

Answer 1

Answer: when the dipole moment and electric field are parallel

Explanation: The formulae that relates the potential energy of a dipole, dipole moment and strength of electric field is given as

u = p * E cosθ

Where, u= dipole potential energy, p = dipole moment, E = strength of electric field.

The expression is at maximum when θ = 0 (cos 0° = 1)

Hence the function for potential energy will be greatest when θ = 0° which implies that the dipole moment and strength of electric field are parallel to each other.